Punctuation, an element of Mechanics in written discourse, refers to printed symbols that are used to clarify relationships between words, phrases, and clauses in a sentence.


In written Standard American English, there are a number of guidelines for punctuation usage. Some guidelines are firmer than others. For example, it is almost always considered an error to separate two complete sentences with a comma (which creates a comma splice). However, far fewer style guides agree about when a sentence’s opening phrase must be followed by a comma.

The concept of “correct punctuation” changes based on writing content and style. Some punctuation guidelines are consistent across writing situations, but sometimes you’ll have to adopt different punctuation guidelines to adapt to different audiences, genres, and styles. When you’re writing, consult with relevant style guides and experts (like your instructor) to make sure you’re following the appropriate guidelines for your writing situation.

AmpersandApostrophe AsterisksBrackets
BulletsColonsCommasDashes
EllipsisEnd Punctuation (Exclamation Point, Question Mark, Period)Exclamation PointHyphens
Italics Parentheses Period
Question Marks
Quotations Semicolons

A punctuation problem occurs when punctuation marks are used incorrectly or are not used when they should be. Punctuation problems can involve a variety of punctuation marks, including quotation marks, dashes, commas, semicolons, periods, question marks, exclamation points, and parentheses.

How can I tell if I have a punctuation problem?

Punctuation problems can be hard to spot.

The easy ones to fix may be just a matter of proofreading: Did you include a closing quotation mark somewhere after the opening one? Do all of your sentences have end punctuation, like a period or a question mark?

The more complex uses of punctuation can create problems that are hard to spot, though. Based on feedback from instructors, writing center tutors, and other readers, identify whether your writing includes recurring punctuation problems.

For example, have multiple readers pointed out that your writing includes unnecessary commas? If so, pay extra attention to the commas you write and ensure that each comma fulfills a function described in the guidelines above or in whatever style guide you’re using. That way, rather than trying to check every single punctuation mark, you’re focusing on a pattern of error that you know might create punctuation problems in your writing.

Ex: Going to the store in the tremendous thunderstorm down pothole-riddled and rain-soaked streets, was a nightmare. Once in the store, Elena bought two, large flashlights.

In the first sentence, the comma separates the subject (going to the store in the tremendous thunderstorm down pothole-riddled and rain-soaked streets) from the verb, (was). Commas should never separate subjects and verbs.

In the second sentence, the first comma separates an introductory phrase (once in the store) from the rest of the sentence (Elena bought two, large flashlights). According to most style guides, this is an acceptable use of commas.

The second comma, however, separates the number of flashlights (two) from the adjective describing the flashlights (large). Words in front of and modifying a noun only need to be separated by commas when they are adjectives. This is an unnecessary comma.

Revised: Going to the store in the tremendous thunderstorm down pothole-riddled and rain-soaked streets was a nightmare. Once in the store, Elena bought two large flashlights.

If you notice or if a reader tells you about a regular pattern of punctuation errors, like this overuse of commas, pay close attention to your usage of that punctuation mark. Also, familiarize yourself with and apply the relevant style guide’s usage rules for that punctuation mark.

How can I revise a punctuation problem?

Revision strategies for punctuation problems vary widely depending on the exact nature of the problem. Typically, you can revise in one of these three ways:

  • Add punctuation. For example, in the sentence “My greatest heroes are my parents, Gandhi and Oprah Winfrey,” the writer seems to imply that the parents are Gandhi and Oprah Winfrey. More likely, the author meant that her parents and Gandhi and Oprah Winfrey are her greatest heroes. To make this second meaning clear, the author could add a comma after Ghandi: “My greatest heroes are my parents, Gandhi, and Oprah Winfrey.”
  • Subtract punctuation. For example, in the sentence, “Kerri claimed to have “evidence” of Trevor’s impropriety,” the quotation marks act like ironic air quotes. They imply that Kerri’s evidence might not exist or be all that implicating, which casts a negative light on Kerri. If the author does not mean to imply all this, the quotation marks should be subtracted: “Kerri claimed to have evidence of Trevor’s impropriety.”
  • Replace punctuation. For example, in the sentence “I don’t know whether to go to Brazil or not?” the question mark is incorrect because the sentence doesn’t actually ask a question. Instead, it makes a statement about the author’s indecision (which could, of course, prompt the author to ask someone a question like “Do you think I should go to Brazil or not?”). The question mark should be replaced with a different end-of-sentence punctuation mark: “I don’t know whether to go to Brazil or not.” or “I don’t know whether to go to Brazil or not!”